Windows 7 boot processes and partitions
“I took a serious a++ kicking trying to load XP after W7 - soooo - I removed 7 HDD and reloaded XP - I now have XP loaded and I am about to connect W7 -
Question - should I load BCD before I connect ?
I will persevere until I have a dual boot system ....”
“Thank you so much for your help - it is so typical of the new millennium MS to complicate the crap out of everything - Vista/W7 is like taking a fat chick with an eating disorder to an expensive restaurant - you'll regret the hell out of it ... were I more "tech savvy" I would drop MS and go for the open source programs ...
again thanks for your time
Tigere”
Microsoft had to change the way Windows boots starting the Windows Vista. The way operating systems have been booting for a long time with the BIOS (basic input/output system) has become a problem for servers because the technology is outdated. Also there is a 2 TB (terabyte) single partition limit that is going to be a real headache for consumers but would like to have a single C drive. All the major operating system vendors have made their OS’s capable of exceeding this limit but the motherboard manufacturers have not yet.
http://www.pctechguide.com/11Motherboards_EFI.htm
http://en.wikipedia.org/wiki/Extensible_Firmware_Interface
“There is indeed a 2TB barrier (sorta), but it only applies to boot partitions, not all drives. And not just in Windows XP; it’s a long-standing limitation that is finally being reached by hardware.
Back in the Stone Age, floppy disks were formatted into tiny chunks—512-byte sectors, to be precise. In order to find data on a disk, the drive needs to know where to look, so each sector has an address that the Master Boot Record uses to locate information. The MBR stores disk partition information as 32-bit integers, meaning it can address a maximum of 4,292,964,296 512-byte sectors, or 2,199,023,255,552 bytes. Look familiar? It’s 2.2 tebibytes, or 2TB. Since the MBR can’t allocate addresses to partitions with more than 2TB worth of 512-byte blocks, you can’t boot from them. No problem if you’re booting from another drive, but a bummer for people who really want a massive boot partition.
The solution, as discussed in our June 2010 White Paper, is three-fold. You’ll need a motherboard that uses Extensible Firmware Interface (or EFI) instead of the 32-bit BIOS that’s standard, a GPT-initialized drive (as opposed to MBR), and a 64-bit version of Vista, Windows 7, Linux, or OS X. Only then will you be able to boot from a partition greater than 2TB. Manufacturers have resisted transitioning from BIOS/MBR to EFI/GPT, but as physical drives with more than 2TB of storage become a reality, they may finally have to comply.”
http://www.maximumpc.com/article/ask_doctor/why_2tb_ceiling
Windows XP came out in 2002. It’s very obsolete technology. With a basic single hard drive setup you can just put in the Windows XP install disc and make a single primary partition. Whatever boot files Windows XP needs will end up in the same partition with all the rest of your data. If you do much work with files it’s pretty easy to delete your boot files with this type of setup.
It’s been common practice amongst us who boot multiple operating systems to make a small primary partition at the front of the drive to boot multiple OS’s out of and to possibly run DOS. If one makes a primary partition of say 100 MB at the front of the hard disk and then formats the rest of the hard disk as an extended partition, then makes many logical partitions in the extended partition, you can load Windows XP into any logical partition that you wish. Windows XP’s boot files will end up in the first primary partition. This is what I call a boot partition. Microsoft calls it a system partition.
If you do a basic load of Windows 7 and specify say a 55-GB partition, Windows 7 will go behind your back and automatically make a 100-MB boot partition at the front of the drive. Both of these will be primary. The same applies to Windows Vista.
Note that on any system, whether you have one or multiple hard disks or not, only one primary partition can be active at a time. The BIOS hands over control to the active partition. When a system boots the control passes from the BIOS to the primary active partition to the partition in which the OS is on to the file in the partition which starts the OS.
Windows XP boot process:
http://neosmart.net/wiki/display/EBCD/Windows+XP
You could have for example, installed Windows 7 on the first hard disk. Then you could have installed Windows XP in a logical partition on the second hard disk. The boot files for Windows XP would end up in the boot partition on the first hard disk and would temporarily destroy the ability to boot into Windows 7. You could then use the Windows 7 recovery disk to restore the boot process for booting into Windows 7. You could then install Easy BCD into Windows 7. You could then add a boot option for Windows XP in Easy BCD.
Alternatively you could have made a boot partition of 100 MB at the front of the first hard disk. Then make the entire second hard disc an extended partition. Then make a logical partition within the extended partition. Load windows XP into the logical partition within the extended partition on the second hard disk. Then install Windows 7 on the first hard disk. Windows 7 will pick up a boot option for Windows XP automatically. But if you want to use the prettier Easy BCD boot loader you can install Easy BCD in Windows 7 and add the entry to boot into Windows XP there.
Having a primary partition at the front of both hard drives in a two hard drive system makes things more problematic. I think it’s best that if you want to use a second hard drive, that you make sure that there are no active partitions on the second hard drive.